Fungicidal and fungistatic thiocarbonates

ABSTRACT

Novel thiocarbonates of the formula

United States Patent Hoyer et al.

[ Jan. 29, 1974 F UNGICIDAL AND FUNGISTATIC THIOCARBONATES Inventors: Georg-Alexander Hoyer; Ernst Albrecht Pieroh, both of Berlin, Germany Schering AG., Berlin and Bergkamen, Germany Filed: Mar. 31, 1970 Appl. N0.: 24,375

Assignee:

Foreign Application Priority Data Apr. 24, 1969 Germany 1921988 US. Cl. 260/455 B, 260/347.5, 424/285,

424/301 Int. Cl. C07c 154/00 Field of Search 260/455 B, 347.5; 424/301 References Cited UNITED STATES PATENTS 8/1966 Louthan 260/455 B Hoyer et a1. Fungicidal Alkyl N-(dimethylaminoalkyl) Carbarnates and Thiocarbamates, (1968), CA71, No. 60112P (1969).

Primary Examiner-Glennon H. Hollrah Attorney, Agent, or Firm-Joseph F. Padlon [57] ABSTRACT Novel thiocarbonates of the formula (CH N(CH OCOSR wherein R is the radical of an aliphatic hydrocarbon, and their salts with inorganic or organic acids are provided having fungicidal and fungistatic effects and the method of making the same.

1 Claim, N0 Drawings FUNGICIDAL AND FUNGISTATIC THIOCARBONATES The invention relates to novel thiocarbonates having fungicidal and fungistatic effects, to the use of the compounds as fungicidal and fungistatic agents, and to methods of preparing the same.

Among the known active agents having fungicidal effects are tetramethylthiuram disulfide, N- trichloromethylthio-4-cyclohexene-1 ,2-dicarboximide, and 5ethoxy-3-trichloromethyll ,2,4-thiadiazole.

Fungicidal and fungistatic N-dialkylaminoalkyl carbaminic acid esters and corresponding thiocarbaminic acid esters have been described in Belgian Pat. No. 708,057.

It has now been found that compounds of the formula wherein R is the radical of an aliphatic hydrocarbon, and their salts with inorganic or organic acids have fungicidal and fungistatic effects which are surprisingly greater than those of known compounds employed for similar purposes.

The invention therefore relates to new compounds of the above formula, to their use as fungicidal and fungistatic agents, and to methods of preparing the compounds.

The compounds of the invention are particularly effective against fungi causing damping-off disease which are very difficult to control, such as Pythium ultimum. Another advantage is the excellent tolerance by plants to the use of these compounds.

They may therefore be employed, for example, in agriculture and in horiculture as seed disinfectants or for general soil treatment for their fungicidal and fungistatic effects on the soil.

The novel compounds may be employed alone or in mixtures of several active agents. Furthermore and optionally, other fungicides, nematocides, herbicides, seed disinfectants or other parasite control agents may be added, depending on the desired purpose. The compounds are preferably used in the form of compositions, such as powders, spreadable compositions, granulates, solutions, emulsions or suspensions, with added liquid and/or solid carriers or diluents, and optionally with wetting, adhesion improving, emulsifying and/or dispersing agents.

Suitable liquid carriers are water, mineral oils or other organic solvents such as xylene, chlorobenzene, cyclohexanol, cyclohexanone, dioxan, acetonitrile, ethyl acetate, dimethylformamide and dimethylsulfoxide, and others.

Solid carriers which are suitable include limestone, kaolin, chalk, talcum, attaclay and other clays as well as natural or synthetic silica.

As surfactants, there may be mentioned the salts of lignosulfonic acids, salts of alkylated benzenesulfonic acids, sulfonated acid amides and their salts, polyethoxylated amines and alcohols.

When the active agents of the invention are to be used for seed treatment, dyes such as neofuchsine and others may be admixed in order to impart a clearly visible color to the treated seeds.

The proportion of the active agent or agents in the compositions may vary within limits, the actual concentration of the active agent in the composition being determined mainly by the rate at which the composition is intended to be used for soil or seed treatment. By way of example, the compositions may contain between about 1 and percent by weight of the active agent and about 99 to 20 percent of liquid or solid carrier and optionally up to 20 percent surfactants in the form of an emulsion or of a solid composition.

The novel compounds are prepared, for example, by reacting gamma-dimethylaminopropanol of the formula (CH =N(CH -OH with a compound of the formula RS--COl-lal wherein R is the radical of an aliphatic hydrocarbon and Hal is halogen, preferably chlorine, in the presence of an acid acceptor, optionally followed by treatment with an inorganic or organic acid.

Suitable acid acceptors are, for example, tertiary organic amines, such as triethylamine or pyridine and others, inorganic bases, such as alkali metal hydroxide or carbonate and others, or the gammadimethylaminopropanol employed as a reactant which is then used in a correspondingly greater amount.

The reaction is preferably carried out with the use of an inert solvent, for example, an ether or a liquid hydrocarbon and the like, either as a single-phase or a two-phase reaction, the latter with the addition of nonmiscible liquids, for example, water and an organic liquid not miscible with the same.

The reaction proceeds preferably in the temperature range of about 0 to 100C, but it can be carried out also at higher and lower temperatures.

The salts may be prepared by the action of an organic or inorganic acid on the thiocarbonate. As suitable acids, an'y inorganic or organic acid, such as mineral acids, monoor polycarboxylic acids and sulfonic acids may be considered of which the following are mentioned: hydrochloric acid, sulfuric acid, formic acid, propionic acid, valeric acid, oxalic acid, malonic acid, succinic acid, cyanoacetic acid, chloracetic acid, dichloracetic acid, trifluoracetic acid, benzoic acid, furan-2-carboxylic acid, p-toluenesulfonic acid, methanesulfonic acid, thioglycolic acid, citric acid, and the like. Optionally, solvents such as water, ethers, alcohols or liquid hydrocarbons may be employed. The reaction temperature is not critical. After the reaction, the salts formed are recovered in a manner known in the art, for example, by suction filtration.

The salts may also be prepared advantageously in a single stage process in which gammadimethylaminopropanol is reacted with chlorothioformic acid esters with or without solvent at about 20 to 100C, wherein the aminoalcohol derivative itself acts as an acid captor.

The preparation of the compounds of the invention is described hereinbelow in more detail, and is illustrative of the invention.

a. Preparation of the thiocarbonates 0.1 Mole of a chlorothioformic acid ester is added slowly drop by drop to a solution of 0.1 mole gammadimethylaminopropanol and 0.1 mole triethylamine in 200 ml ether with constant stirring. Stirring is continued for several hours, the reaction mixture is then left to stand overnight, whereupon the precipitated triethylamine hydrochloride is filtered off with suction, the filtrate is then evaporated, and the residue is fractionated in a vacuum. The yield is between 70 and 80 percent of theory.

b. Preparation of the salts thiocarbonate is dissolved in 150 ml of absolute ether. l-lCl gas is then introduced with stirring and cooling until no further precipitation occurs. The precipitate is;

recovered by suction filtration and dried over phosphorus pentoxide. The yields are between 80 and 90 percent of theory.

According to another method, 0.15 mole chlorothioformic acid ester is dissolved in 200 ml of absolute ether. 0.15 Mole gamma-dimethylaminopropanol in 200 ml of absolute ether is added slowly dropwise with stirring at -36C. Stirring is continued for 2 hours and the resultant precipitate is filtered off with suction and dried over phosphorus pentoxide. The yields are between 85 and 95 percent of theory.

The following compounds are representative of the invention:

The free bases are soluble or very soluble in organic solvents such as ether, ethanol, acetone, benzene, chloroform, acetonitrile, ethyl acetate, dimethylformamide, dimethylsulfoxide, pyridine and the like, whereas the salts dissolve well or very well in water, methanol, ethanol and chloroform.

The following examples illustrate the fungicidal and fungistatic effects of the compounds of the invention.

EXAMPLE 1 Sterilized compost soil was inoculated with mycelium of Pythium ultimum. Peas of the strain Wonder of Kelvedon, treated with suitable compositions of the active agents to be tested were seeded in clay dishes having a soil capacity of 2 liters at a depth of 2 to 3 cm, at seeds per concentration. After a cultivation period of 14 days at a temperature of 22-25C, the number of germinated peas in percent was determined. Known active agents were used as controls. The com- Number of germinated peas,

Physical Constants n 1.4640 O-gamma-dimethylaminopropyl-S-ethyl thiocarbonate B.P., llO-l 12C 1 2. n l.4655 O-gamma-dimethylaminopropyl-S-propyl thiocarbonate By. l23-l24C 3. M.P. l-l67C Ogamrna-dimethylaminopropyl-S-ethyl thiocarbonate hydrochloride (decomp.) 4 M.P. l28-l30C 65 O gamma dim ethylaminopropyl-S-propyl thiocarbonate hydrochloride positions employed were powders conainin g 50 percent by weight of the active agent.

"FYA MPTEQ Steamed compost soil was inoculated with mycelium of Pythium ultimum. Peas of the strain Wonder of Kelvedon, treated with compositions containing 10 percent active agents, were seeded in clay dishes holding 2 liters of soil at a depth of 2 to 3 cm, at 50 seeds per concentration. After a cultivation time of 14 days at a temperature of 2225C, the number of germinated peas was determined in per cent. Known active agents were used as controls.

a Number of germinated peas, per cent Compound Active agent per kg seed 0.2 g 0.3 g 0.4 g

O- y-Dimethylaminopropyl-S- 86% v 84 7 m propyl thiocarbonate hydrochloride Control 5-ethoxy-3-trichloromethyl- 8% liif i 7 20%? 1,2,4-thiadiazole N-Trichloromethylthio-cyclo- 24% 26% 36% hexene-l ,2-dicarboximide U V i V Steamed soil, untreated seeds 96% 96% 98% Infested soil, untreated seeds 0% 0% EXAMPLE 3 15 What is claimed is:

Clay dishes having a soil capacity of 2 liters were Compounds of the formula filled with compost soil that had not been steamed. The

compositions were spread per 20 cm of furrow in the 3 form of a powder containing l0 percent of the active N-(CHz)ragent. There followed the seeding of 30 seeds per con- 20 centration of cotton seeds from which lint had been re- 3 moved. The number of germinated healthy cotton seeds and the weight of the fresh plants after a cultivawherein R is the radical of a saturated aliphatic hydrotion period of 14 days at a temperature of 22-25C are carbon having from two to three carbons, and their hylisted below. As a control, N-trichloro-methylthio-4- 25 drochloric acid salts. cyclohexene-l,Z-dicarboximide was employed.

mg active Number Weight of agent per of healfresh Compound 20 cm furrow thy plants plants, g

O-y-DimethylaminopropylS-propyl 5 mg 27 l8 g thiocarbonate hydrochloride 10 mg 27 20 g 20 mg 27 18 g 40 mg 28 19 g O-y-Dimethylaminopropyl-S-ethyl 5 mg 2l g thiocarbonate hydrochloride 10 mg 24 19 g 20 mg 28 22 g mg 28 22 g Control N-Trichlor0methylthio-4- 5 mg 9 6 g cycl0hexene-l ,2-dicarboximide 10 mg l8 12 g 20 mg l2 9 g 40 mg 16 10 g Steamed soil 30 22 g 29 l9 g 30 20 g Untreated soil 0 1 2 l g 

